Rounded invasive electrohydraulic lithotripsy probe with ports

ABSTRACT

A lithotripter tip configured for use within an invasive lithotripter probe may include a lithotripter tip body dimensioned and configured to be threaded through a human vein or artery of a patient and delivered to a position directly adjacent to a concretion within the patient. The lithotripter tip body may define an interior region in communication with an aperture at a distal end of the lithotripter tip body and the lithotripter tip body may define at least one port in communication with the interior region that is configured to receive a liquid and provide a path for the liquid to flow into the interior region of the body. A first electrode and a second electrode are positioned within the interior region of the lithotripter tip such that such that when liquid from the at least one port is within the interior region and an electric arc occurs between the ends of the first and second electrodes, a gaseous bubble forms within the interior region and a resulting shockwave travels out of the aperture at the distal end of the lithotripter tip body and impacts the concretion positioned directly adjacent to the lithotripter tip body.

RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 15/398,987, filed Jan. 5, 2017, which claims priority to U.S.Provisional Pat. Appln. No. 62/275,999, filed on Jan. 7, 2016, theentirety of each of which are hereby incorporated by reference.

BACKGROUND

Electrohydraulic lithotripsy has been used in the medical field,primarily for breaking concretions in the urinary or biliary tract. Therecent introduction of endoscopes, such as Boston Scientific's SpyScope®, Olympus's Mother/Daughter Gastroscope, and ACMI's flexibleureteroscopes, that are designed to reach more remote locations in thebody, such as the common duct, hepatic duct, kidney, ureter, andbladder, have increased the need for electrohydraulic lithotripsy probesthat can more easily access remote locations in patients.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one implementation of anelectrohydraulic lithotripsy probe (EHL probe).

FIG. 2 is a cross-sectional side view of the EHL probe of FIG. 1 .

FIG. 3 is a side view of the EHL probe of FIG. 1 .

FIG. 4 is a front view of the EHL probe of FIG. 1 .

FIG. 5 is a top view of the EHL probe of FIG. 1 .

FIG. 6 is a perspective view of another implementation of an EHL probe.

FIG. 7 is a cross-sectional side view of the EHL probe of FIG. 6 .

FIG. 8 is a side view of the EHL probe of FIG. 6 .

FIG. 9 is a front view of the EHL probe of FIG. 6 .

FIG. 10 is a top view of the EHL probe of FIG. 6 .

FIG. 11 is a perspective view of another implementation of an EHL probe.

FIG. 12 is a cross-sectional side view of the EHL probe of FIG. 11 .

FIG. 13 is a side view of the EHL probe of FIG. 11 .

FIG. 14 is a front view of the EHL probe of FIG. 11 .

FIG. 15 is a top view of the EHL probe of FIG. 11 .

FIG. 16 is a perspective view of another implementation of an EHL probe.

FIG. 17 is a front view of the EHL probe of FIG. 16 .

FIG. 18 is a side view of the EHL probe of FIG. 16 .

FIG. 19 is a rear view of the EHL probe of FIG. 16 .

FIG. 20 is a cross-sectional side view of the EHL probe of FIG. 16 .

FIG. 21 is a perspective view of another implementation of an EHL probe.

FIG. 22 is a front view of the EHL probe of FIG. 21 .

FIG. 23 is a side view of the EHL probe of FIG. 21 .

FIG. 24 is a rear view of the EHL probe of FIG. 21

FIG. 25 is a cross-sectional side view of the EHL probe of FIG. 21 .

FIGS. 26 a and 26 b are diagrams illustrating example shockwaves createdby some implementations of an EHL probe.

FIG. 27 is a flow chart of a method for using a rounded EHL probe withports.

DETAILED DESCRIPTION OF THE DRAWINGS

In order to fragment and destroy stones or other concretions in remotelocations within the body, an endoscope and other instruments mustmaneuver through tortuous paths to achieve proper positioning fordiagnostic and operative procedures. In some cases, EHL probes arethreaded through bends as sharp as between 90 and 120 degrees, and evenup to 180 degrees. It can be extremely difficult to thread conventionalEHL probes through these tortuous paths partially because of a lack ofsufficient stiffness in the lithotripsy probe and their geometric shapethat typically include square or slightly beveled edges. Moreover,conventional scopes and catheters often develop creases or “wrinkles” onthe inner walls of their lumens due to the tortuous bends and frictionalforces created by the lumen materials that cause the edges of the probesto become lodged or wedged in the scope or catheter lumens. Further,sharp or squared off edges of conventional laser fibers, ultrasoundwands, and mechanical (ballistic) lithotripter probes can easily scrapeor perforate the delicate body lumens they are threaded through.

The present disclosure is directed to invasive EHL probes that may besafely threaded through veins, arteries, ureters, and/or scope orcatheter lumens to be positioned less than one millimeter or directlyadjacent to concretions in remote locations within a patient. Generally,implementations of the disclosed EHL probes include rounded featurespositioned at leading surfaces of the EHL probe. These rounded featuresat the leading surfaces of the EHL probe typically come into contactwith interior walls of veins, arteries, ureters, and/or scope lumenswhen the EHL probe is threaded through a patient's body. The roundedfeatures reduce frictional forces with the interior walls, therebyreducing the formation of frictional forces in the creases and wrinklesin the inner walls of the veins, arteries, ureters, and/or scope orcatheter lumens, as well as being less traumatic to tissue. The roundedfeatures may further be coated with hydrophilic compounds to furtherreduce frictional forces. Coatings that could be used are commerciallyavailable formulations supplied by companies such as Biomet in OakvilleOntario, Biocoat in Horsham Pa., or Surface Solutions Group in ChicagoIll.

Additionally, implementations of the disclosed EHL probes may compriseone or more ports that allow liquid from the surrounding fluidenvironment to flow into the probe tip without the need to inject salineor other liquid for irrigation through a port into the probe tip tocreate the desired hydraulic effect. There is no need to force fluidinto the tip with these implementations, thereby allowing for a smallerprobe shaft diameter as there is no need to include a separate channelto force irrigant through the channel and into the tip.

When an electric arc occurs between electrodes positioned in theinterior region of the EHL probe, a gaseous bubble forms within theinterior region. The gaseous bubble rapidly expands and contracts backon itself, thereby creating a pressure wave (a shockwave) in the liquid.The shockwave exits the interior region through an aperture at a distalend of the EHL probe and is focused against a stone or concretionpositioned directly against to the EHL probe. Because the EHL probe ispositioned directly against the stones or concretions, the potential todamage tissue adjacent to the stone or concretions is reduced whencompared to conventional EHL probes that may not be positioned directlyadjacent to the stone or concretion. Example shockwaves that thedescribed EHL probes may create are shown in FIGS. 26 a and 26 b.

FIGS. 1-5 illustrate one implementation of an invasive EHL probe 100.The EHL probe includes a lithotripter tip body 102 that may comprisemetal, plastic, or “glass” like materials that provide a smooth surfacefree or substantially free from burrs, noticeable grooves orprotrusions. The lithotripter tip body 102 may be coated or plated with,but not limited to, copper, silver, or gold, for example. In someimplementations, the metal is stainless steel, the circumference of therounded tip body is equidistant from its center, has a radius ofapproximately 0.4 mm-1.0 mm, and the rounded tip is polished to give ita smooth surface.

The lithotripter tip body 102 defines at least a rounded portion 104 anda cylindrical portion 106. The rounded portion 104 is positioned at adistal end of the EHL probe 100 and the cylindrical portion 106 ispositioned adjacent to the rounded portion 104. In some implementations,the rounded portion 104 may be donut shaped as shown in FIGS. 1-5 ,circular shaped as shown in FIGS. 6-10 , or bead shaped as shown inFIGS. 11-15 so long as a leading surface of the EHL probe 100 presents arounded surface to inner walls of a vein, artery, and/or lumen as theprobe is threaded through a body of a patient.

A radius 108 of the rounded portion 104 is greater than a radius 110 ofthe cylindrical portion 106. Because the rounded portion 104 may extendfarther from the lithotripter tip body 102 than the remainder of thelithotripter tip body 102, the rounded portion 104 is more likely tocome into contact with inner walls of a vein, artery, and/or lumen asthe EHL probe 100 is threaded through a body of a patient and positioneddirectly against a stone or concretion. It will be appreciated that therounded portion 104 of the lithotripter tip body 102 reduces oreliminates the frictional forces that can cause creases or “wrinkles” todevelop on the inner walls of a vein, artery, and/or lumen, and is lesstraumatic to the tissue.

In some implementations, the diameter of the rounded portion 104 is 1.5millimeters or less. However, the size of the rounded portion 104 may belarger based on available lumen, endoscope, or the body area beingaccessed.

The lithotripter tip body 102 defines an interior region 112 with anaperture 114 positioned at the rounded portion 104 of the lithotriptertip body 102. In some implementations, the aperture 114 is flush withthe rounded portion 104 of the lithotripter tip body 102 to reduce anamount of friction that the surface of the EHL probe 100 may cause as itis threaded through a vein or artery.

The lithotripter tip body 102 defines one or more ports 116 that are incommunication with the interior region 112. The ports 116 are configuredto provide a pathway to allow a liquid such as saline into the interiorregion 112. In some implementations, the ports 116 are between 0.007 and0.014 inches in width or diameter.

A first electrode and a second electrode are positioned within theinterior region 112 of the EHL probe 100. In some implementations, thefirst or second electrodes may be a conductive version of the roundedtip, or two separate conductors residing within the tip. As known in theart, the first and second electrodes are coupled with an electricalsource, such as an electrohydraulic generator (AUTOLITH® generator,supplied by Northgate Technologies Inc.), used to charge the firstelectrode to one polarity and the second electrode to an oppositepolarity.

When the first electrode is charged to a first polarity and the secondelectrode is charged to a second, opposite polarity, a discharge ofelectricity occurs between the first and second electrodes (anelectrical arc) when the potential between the first and secondelectrodes reaches the breakdown voltage for the media separating theelectrodes.

When the interior region 112 of the EHL probe includes liquid such assaline, an electrical arc between the first and second electrodes causesa gaseous bubble in the interior region 112. The gaseous bubble rapidlyexpands and contracts back on itself. As the gaseous bubble contracts, apressure wave (a shockwave) is created in the liquid within the interiorregion 112. The shockwave exits the interior region 112 at the aperture114 positioned at the distal end of the EHL probe 100 where it impacts astone or concretion positioned directly adjacent to the EHL probe 100.

A strength of an EHL shockwave when it impacts a concretion is afunction of a distance between the concretion and the EHL probe thatcreated the shockwave. The further away from the concretion the EHLprobe is, the weaker the shockwave becomes when it impacts theconcretion. Conventional EHL probes require a distance of at least 2 mmbetween the concretions and the EHL probe so that the pressure bubblehas adequate space to form. However, with the EHL probes 100 of thepresent disclosure, the EHL probe 100 may be positioned directly againstthe concretion, thereby providing a stronger shockwave to impact theconcretion when compared to conventional EHL probes. This is possiblebecause the fluid that enters the probe tip through the port conductsthe spark and the inside of the probe tip has sufficient space allow thebubble to form within the EHL probe 100. As the bubble escapes from thedistal end of the EHL probe 100, the interior region 112 of the EHLprobe 100 restricts a shockwave to reduce an amount of lateral pressurecaused by the expanding and contracting “bubble” and directs theshockwave towards the aperture 114 at the distal end of the EHL probe100. Accordingly, the body of the EHL probe 100 limits any unintendedlateral forces from being projected to surrounding tissue, and directsthe shockwave directly to a surface of the concretion.

Another implementation of an EHL probe 1600 is shown in FIGS. 16-20 .The EHL probe 1600 includes a cylindrically shaped lithotripter tip body1602. Similar to the EHL probes described above, a leading edge 1604 ofthe lithotripter tip body 1602 is rounded to reduce or eliminatefrictional forces that can cause creases or “wrinkles” to develop oninner walls of veins, arteries, and/or ureter when the EHL probe 1600 isthreaded through veins, arteries, and/or ureter.

The lithotripter tip body 1602 defines an interior region 1606 and anaperture 1608 in communication with the interior region 1606. Theaperture 1608 is positioned at a distal end of the lithotripter tip body1602 and in some implementations is flush with the rounded leading edge1604 of the lithotripter tip body 1602.

The lithotripter tip body 1602 additionally defines one or more ports1610 in communication with the interior region 1606. The ports 1610provide a pathway to inject a liquid such as saline into the interiorregion 1606. In some implementations the ports 1610 may be elongatedovals such as those shown in FIGS. 16-20 , wherein in otherimplementations the ports 1608 may be other shapes such as the circularports 1608 shown in FIGS. 21-25 .

A first electrode and a second electrode are positioned within theinterior region 1606 of the EHL probe 1600. As known in the art, thefirst and second electrodes are coupled with an electrical source, suchas an electrohydraulic generator (AUTOLITH®, supplied by NorthgateTechnologies Inc.), used to charge the first electrode to one polarityand the second electrode to an opposite polarity.

When the first electrode is charged to a first polarity and the secondelectrode is charged to a second, opposite polarity, a discharge ofelectricity occurs between the first and second electrodes (anelectrical arc) when the potential between the first and secondelectrodes reaches the breakdown voltage for the media separating theelectrodes.

When the interior region 1606 of the EHL probe includes liquid such assaline, an electrical arc between the first and second electrodes causesa gaseous bubble in the interior region 1606. The gaseous bubble rapidlyexpands and contracts back on itself. As the gaseous bubble contracts, apressure wave (a shockwave) is created in the liquid within the interiorregion 1606. The shockwave exits the interior region 1606 at theaperture 1608 positioned at the distal end of the EHL probe 1600 whereit impacts a stone or concretion positioned directly adjacent to the EHLprobe 1600. In some implementations, the interior region 1606 isconfigured to restrict lateral pressure from the shockwave that forms inthe interior region 1606 and to focus the shockwave to the distal end ofthe EHL probe 1600.

A strength of an EHL shockwave when it impacts a concretion is afunction of a distance between the concretion and the EHL probe thatcreated the shockwave. The further away from the concretion the EHLprobe is, the weaker the shockwave becomes when it impacts theconcretion. Conventional EHL probes require a distance of at least 2 mmbetween the concretions and the EHL probe. However, with the EHL probes1600 of the present disclosure, the EHL probe 1600 may be positioneddirectly against the concretion, thereby providing a stronger shockwaveto impact the concretion when compared to conventional EHL probes.

FIG. 27 is a flow chart of a method for using a rounded EHL probe withports. The method begins at step 2702 with threading an invasivelithotripter probe through a human vein or artery to position thelithotripter probe directly adjacent to a concretion within a patient.In some implementations, the invasive lithotripter probe may be a probesuch as those described above where the lithotripter probe comprises alithotripter tip body that defines at least a cylindrical portion and arounded portion, the rounded portion is positioned at a distal end ofthe lithotripter tip, the cylindrical portion is positioned adjacent tothe rounded portion, and a radius of the rounded portion is greater thana radius of the cylindrical portion.

At step 2704, a liquid such as saline is inserted or flows into theinterior region of the lithotripter tip body via at least one port thatprovides a path for liquid to flow into the interior region.

At step 2706, an electric arc is generated between a first electrode anda second electrode positioned within an interior region of thelithotripter probe tip, wherein the electric arc causes a gaseous bubbleto form within the interior region of the lithotripter probe and aresulting shockwave to travel from the interior region through anaperture at the distal end of the lithotripter tip and to impact theconcretion positioned directly adjacent to the lithotripsy probe.

FIGS. 1-27 illustrate implementations of invasive EHL probes that may besafely threaded through veins, arteries, and/or ureter to be positioneddirectly adjacent to concretion in remote locations within a patient.Rounded features at leading surfaces of the EHL probes reduce frictionforces with interior veins arteritis, and/or ureter, thereby reducingthe formation of creases and wrinkles in the inner walls of the veins,arteries, and/or ureter. The disclosed EHL probes may also include portsthat are utilized to inject a liquid such as saline into an interiorregion of the EHL probe.

It is intended that the foregoing detailed description be regarded asillustrative rather than limiting, and that it be understood that it isthe following claims, including all equivalents, that are intended todefine the spirit and scope of this invention.

The invention claimed is:
 1. A method for performing invasivelithotripsy, the method comprising: threading an invasive lithotripterprobe through a human vein or artery to position the lithotripter probeadjacent to a concretion within a patient, wherein: the lithotripterprobe comprises a lithotripter tip body that defines an interior regionin communication with an aperture at a distal end of the lithotriptertip body; an exterior of the lithotripter tip body defines at least acylindrical portion and a rounded portion, wherein the rounded portionis positioned at the distal end of the lithotripter tip body, thecylindrical portion is positioned adjacent to the rounded portion, and aradius of the rounded portion is greater than a radius of thecylindrical portion; and the exterior of the lithotripter tip bodydefines at least one side port at the rounded portion of the exteriorthat is in communication with the interior region of the lithotriptertip body, where the at least one side port is configured to receive aliquid from an environment exterior to the lithotripter tip body andprovide a path for the liquid to flow from the environment and into theinterior region; inserting liquid into the interior region of thelithotripter tip body via the at least one side port at the roundedportion of the exterior; and generating an electric arc between a firstelectrode and a second electrode positioned within the interior regionof the lithotripter probe tip, wherein the electric arc causes a gaseousbubble to form within the liquid in the interior region of thelithotripter probe and a resulting shockwave to travel from the interiorregion through the aperture at a distal end of the lithotripter tip andto impact the concretion positioned directly adjacent to the lithotripsyprobe.
 2. The method of claim 1, wherein the interior region isconfigured to restrict lateral pressure from the shockwave that forms inthe interior region and to focus the shockwave to the distal end of thelithotripter tip.
 3. The method of claim 1, wherein a side port of theat least one side port is between 0.007 and 0.014 inches in width ordiameter.
 4. The method of claim 1, wherein generating an electric arcbetween the first electrode and the second electrode comprises: chargingthe first electrode to a first polarity and charging the secondelectrode to at a second polarity that is opposite to the firstpolarity.
 5. The method of claim 1, wherein threading the invasivelithotripter probe through the human vein or artery to position thelithotripter probe adjacent to the concretion within the patientcomprises: threading the invasive lithotripter probe through the humanvein or artery to position the lithotripter probe directly adjacent tothe concretion within a patient.
 6. The method of claim 1, wherein thelithotripter probe is positioned less than 2 mm from the concretionwithin the patient.